Display screen or portion thereof with a medical charting user interface



The FIGURE is a front view of a display screen or portion thereof with a medical charting user interface.

The outermost broken lines illustrate a display screen or portion thereof and form no part of the claimed design. The remaining broken lines illustrate portions of the user interface that form no part of the claimed design. 

CLAIM The ornamental design for a display screen or portion thereof with a medical charting user interface, as shown and described. 